This invention relates generally to electronic waveguide switches and particularly relates to a latching switch of the type having a junction ferrite and a driver ferrite.
Electronic waveguide switches are well known in the art. They usually comprise a ferrite junction or switching element disposed in the center of a three port waveguide. The ferrite junction is conventionally provided with a switching coil, the wires extending through the ferrite and the waveguide. Such an electronic latching switch has, for example, been disclosed in a paper by Passaro, et al. entitled "A 35-GHz Latching Switch," which is published in IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-14, No. 12, December 1966, pages 669 through 672.
Electronic latching switches of this type present serious manufacturing problems. Thus the ferrite consists of a three sided body of generally prismatic shape extending towards the three waveguides. It additionally is provided with an impedance matching transformer also extending into each of the three waveguides. The design of such a waveguide presents severe problems because the configuration does not lend itself to analytical design. Hence by cut and try technique various configurations must be evaluated until the proper shape is found which will rotate an electronic signal through +120.degree. and match the impedance of the waveguide to that of the junction.
Additionally the size of the wires used for energizing the switching coil cannot be reduced beyond a certain value. Hence in the millimeter wavelength range (from 30 to 300 GHz) the size of the wire is comparable to that of the waveguide. In other words, the driver portion of the ferrite including the switching coil and its wires cannot be reduced in size beyond a certain value. This in turn limits the highest frequency at which such a switch can be used.
It should also be noted that a particular design which has been evolved by many trials and errors is only suitable for one particular wavelength and cannot easily be scaled up or down for other wavelength ranges.
It is accordingly an object of the present invention to provide an electronic waveguide switch of the latching type suitable for the frequency range between approximately 2 and approximately 100 GHz.
Another object of the present invention is to provide an electronic switch of the type discussed which is amenable to mathematical analysis and hence can readily be scaled up or down to suit any particular wavelength range.
A further object of the present invention is to provide such an electronic switch where the functions of switching and latching are separated from the driving function which actually controls the magnetic properties of the switching ferrite.